Sony removed it from the RX1 to sell the RX1R, and sharpness from the RX1R is better.

If you were given an image taken with either RX1 or RX1R, chances are you might have equal chance of picking the right or wrong one. It has become more a marketing gimmick so it makes sense for everybody to flock to it. And overlook more useful attributes.

So then no innovation should ever be introduced to a camera as a new feature, lest it detract from more useful attributes?

I don't think it is unhealthy to introduce innovations, and use of IBIS for AA effect is certainly one. However, it is unhealthy consumerism to be oversold on one development and overlook what could matter more in real world situations in favor of something else that requires pixel peeping.